Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Hypersensitivity Reactions: Immune-Complex Reactions

Hypersensitivity Reactions: Immune-Complex Reactions

Type III hypersensitivity reactions occur when antigen–antibody complexes form and activate the complement system. Normally, these complexes help the clearance of antigens by phagocytes and red blood cells. However, when large numbers of immune complexes are present, they can deposit in tissues—particularly in the walls of blood vessels—leading to inflammation and tissue injury. These deposits trigger complement activation and neutrophil recruitment, resulting in serum sickness, a systemic...

Drug Toxicity: Allergic Reactions

Drug Toxicity: Allergic Reactions

Drug-related allergies are immune-mediated responses triggered by the administration of pharmacological agents. These hypersensitivity reactions are classified based on the immune mechanisms involved. The four primary types—Type I, II, III, and IV—are mediated by different immunological pathways and exhibit distinct clinical manifestations.Type I Hypersensitivity/ IgE-Mediated Reactions: Immunoglobulin E (IgE) immediately mediates Type I hypersensitivity reactions. Upon initial exposure to a...

Allergic Drug Reactions

Allergic Drug Reactions

Allergic reactions related to drugs are hypersensitivity responses driven by the immune system and bear no connection to the drug's therapeutic action. While drugs in isolation do not trigger an immune response, they can interact with endogenous proteins to form antigens. These antigens stimulate lymphocytes to produce antibodies. IgE-type antibodies attach themselves to mast cells. Upon subsequent exposure to the same stimulus, the antigen-antibody interaction is initiated, unleashing numerous...

Hypersensitivities

Hypersensitivities

Hypersensitivity, also known as a hypersensitivity reaction or allergic reaction, is a condition where the body's immune system reacts abnormally to a foreign substance. Such substances, that cause hypersensitivity are referred to as an allergen, could be something typically harmless to most people, like pollen or certain foods.
Types of Hypersensitivities
Hypersensitivity reactions are categorized into four types: Type 1, Type 2, Type 3, and Type 4. Each type has a distinct mechanism...

Hypersensitivity Reactions: Delayed Hypersensitivity Reactions

Hypersensitivity Reactions: Delayed Hypersensitivity Reactions

Delayed-Type Hypersensitivity (DTH), or Type IV hypersensitivity, is a cell-mediated immune response. It occurs when T cells, rather than antibodies, mediate a reaction to specific antigens. It is characterized by a delayed onset (1-2 days) and involves the recruitment of macrophages to the inflammation site.The initiation of a DTH response begins with the sensitization of T cells. During this phase, which lasts at least 1-2 weeks, antigen-specific T cells are activated, clonally expanded, and...

Hypersensitivity Reactions: Cytolytic Reactions

Hypersensitivity Reactions: Cytolytic Reactions

Type II hypersensitivity involves IgG and IgM antibodies targeting cell surface antigens, leading to cell destruction. This can occur through complement activation, antibody-dependent cell-mediated cytotoxicity (ADCC), or acting as opsonins for phagocytosis. When excessive, these reactions cause significant tissue damage.Drug-induced hemolytic anemia is a common example, where drugs like penicillin or cephalosporins bind to red blood cells, forming drug-protein complexes. These complexes...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Topical Roflumilast for Pediatric Morphea.

Journal of cutaneous medicine and surgery·2026

Same author

Cross-Sectional Survey of Unmet Needs in Children With NF1 and Cutaneous Neurofibromas: The Role of Pediatric Dermatology.

Pediatric dermatology·2026

Same author

Pediatric morphea: MRI evaluation of superficial and deep tissue involvement and impact in clinical practice.

Pediatric radiology·2026

Same author

Intravenous immunoglobulin for the treatment of morphea in pediatric patients: A case series.

JAAD case reports·2026

Same author

Canadian real-world evidence: observational 24-week outcomes for health care practitioner authorized cannabis.

Canadian journal of pain = Revue canadienne de la douleur·2026

Same author

Prospective Study to Assess the Utility and Validity of a Chromameter in the Assessment of Infantile Hemangiomas.

Pediatric dermatology·2026

Search research articles

Related Experiment Video

Updated: Jun 25, 2026

Granulocyte-dependent Autoantibody-induced Skin Blistering

Granulocyte-dependent Autoantibody-induced Skin Blistering

Published on: October 12, 2012

Eruptive pyogenic granulomas developing after drug hypersensitivity reaction.

Maria Lourdes Palmero¹, Elena Pope

¹Section of Dermatology, Division of Pediatric Medicine, Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada.

Journal of the American Academy of Dermatology

|February 13, 2009

Summary

Multiple pyogenic granulomas, a common pediatric vascular tumor, can rarely erupt. This case details disseminated pyogenic granulomas following a drug hypersensitivity reaction, exploring potential causes.

Related Experiment Videos

Last Updated: Jun 25, 2026

Granulocyte-dependent Autoantibody-induced Skin Blistering

Granulocyte-dependent Autoantibody-induced Skin Blistering

Published on: October 12, 2012

Area of Science:

Dermatology
Pediatrics
Pathology

Background:

Pyogenic granuloma (lobular capillary hemangioma) is a common pediatric vascular tumor.
Disseminated pyogenic granulomas are an uncommon presentation, though previously documented.

Observation:

This report presents a case of disseminated pyogenic granulomas in a pediatric patient.
The eruption of these lesions occurred subsequent to a drug hypersensitivity reaction.

Findings:

The study investigates the potential pathogenic factors contributing to the formation of disseminated pyogenic granulomas.
A link between drug hypersensitivity and the development of multiple pyogenic granulomas is explored.

Implications:

Understanding the triggers for disseminated pyogenic granulomas can aid in diagnosis and management.
Further research into the pathogenesis of pyogenic granulomas post-hypersensitivity reactions is warranted.